1. Field of the Invention                The present invention relates to a retrieval device connectable to a network, and a retrieval server for providing retrieval services through the network to the retrieval device, as well as a retrieval system including the retrieval device and the retrieval server, and further relates to a retrieval method and a computer-readable program for implementing the retrieval method.        
2. Description of the Related Art
In recent years, various networks such as the Internet have been widely used, and various retrieval services have become available through terminals accessible from the networks. Retrieval conditions, such as one or more key words and update time, are entered by a user into the terminal to define the retrieval conditions for retrieving information on the networks.
Another service utilizing the Global Positioning System has also become available, wherein positional information defined by the Global Positioning System is transmitted to a retrieval server for retrieving available information in the vicinity of the defined position.
As described above, the retrieval system implements retrieval based on the retrieval conditions which have been designated by the user. All of the information about the retrieval conditions is open to a retrieval service provider, even if the information includes private information of the user. However if the security of the retrieval server computer is imperfect, then the information may be leaked to any person.
For example, the retrieval system may provide the user with a location map and shops in the vicinity of the position defined by the user. The positional information is open to the server computer and the retrieval service provider, even if the user intends to keep the positional information confidential.
In order to retrieve residential or housing information, various residential information, such as cost and room size, is also open to the server computer and the retrieval service provider.
In order to retrieve job information, a user's professional experience information or educational background, age, and skill information may also become open.
As described above, the information about the retrieval conditions is open to the retrieval service provider, even if the information includes a user's private information or confidential information. This may allow the user's privacy to be invaded.
In the above circumstances, the development of a novel retrieval device for providing a user with retrieval services, with protection of the user's privacy, is desirable.
Further, the development of a novel retrieval server for providing retrieval services through a network to a retrieval device, with protection of the user's privacy, is desirable.
Furthermore, the development of a novel retrieval system, including a retrieval device and a retrieval server, which is capable of protection of a user's privacy is desirable.
Moreover, the development of a novel retrieval method, and a novel computer-readable program for implementing the retrieval method, with protection of the user's privacy is desirable.